The present invention relates to a motor vehicle steering antitheft system.
The invention relates more specifically to a motor vehicle steering antitheft system.
Various designs are known in which the antitheft system comprises a housing in which a member, particularly a key, for manually controlling the starting of the vehicle engine and the locking of the vehicle steering column is inserted and is used in order, or the one hand, to unlock, or release, one shaft of the vehicle steering column in terms of rotation and, on the other hand, to control the starting of the engine and, conversely, to stop the engine and to lock or immobilize the steering column shaft again.
More particularly, the manual control member is mounted so that it can move axially between a pulled back position in which it locks the steering column and a pushed forward position in which it unlocks the steering column.
It is mounted so that it can rotate between at least one angular position of rest and an angular position of use, for example of starting or operating the engine, in which, so as to avoid accidentally immobilizing the steering column during use, particularly when the vehicle is traveling along, it cannot be pulled axially back.
The manual control member is connected in terms of rotation to a rotary output member forming a cam which is capable of collaborating with a latch bolt to control the movements of the latter which is mounted to slide in the housing in a direction which is radial overall with respect to the axis of rotation of the manual control member between a deployed radially outward antitheft position toward which it is elastically urged and in which it projects through an opening of the housing to immobilize in terms of rotation one member of the steering column when the control member is in the angular position of rest and in the pulled back locked position, and a pushed-in position retracted inside the housing.
Finally, the manual control member is connected in terms of rotation to a multi-position switch/interrupter assembly for powering various corresponding electrical circuits, of which there are usually four, and which include, in succession, a xe2x80x9cSTOPxe2x80x9d position (corresponding to the extreme angular position of rest of the manual control member), a xe2x80x9c+ACCESSORIESxe2x80x9d position, a xe2x80x9c+ CONTACTxe2x80x9d position and a xe2x80x9cSTARTxe2x80x9d position (corresponding to the other opposite extreme angular position).
In what is known as a xe2x80x9cmechanicalxe2x80x9d design of such an antitheft system, the manual control member is a key, the shank of which is accommodated axially in the barrel of a lock which, when the key is the right key, allows an output rotor to be turned to control the antitheft latch bolt and the multi-position rotary interrupter.
Successive evolutions in such a type of antitheft system have culminated in particularly reliable and compact designs, it being possible for the entire antitheft mechanism with its lock to be housed, in particular, as a single unit in a tube adjacent to the steering column.
However, it has also been found that it is desirable for certain vehicles to be fitted with more reliable antitheft systems known as xe2x80x9csecurexe2x80x9d systems, while at the same time improving the convenience of use and in particular the ergonomics of manipulation while at the same time meeting the standards, which entails resorting to a manual control member that can move axially and in terms of rotation in order to carry out the aforementioned maneuvering cycles.
In an xe2x80x9celectronicxe2x80x9d antitheft system of this type, the coding of the antitheft system is no longer obtained by the matching of the right key with a barrel-type lock, but is obtained by means of an electronic identification device which, in particular, comprises an electronic identifier belonging to the authorized user and a unit for identifying an authorized user of the vehicle, fitted on board the vehicle, and which supplies an encoded antitheft signal when the correct identifier is recognized.
The electronic device is of the type known as the xe2x80x9chands-freexe2x80x9d type when all the interrogation and recognition or identification steps are performed without the user having to perform any maneuvre or any particular action other than those which allow him to enter the vehicle.
It may also be of the type in which the user has possession of an identifier in the form of a badge which he introduces manually into a housing on board the vehicle.
Designs have thus beer proposed in which the manual member or controlling the antitheft mechanism is a control knob replacing the key and which is permanently on the vehicle.
According to the legislation, the immobilization or release of the steering column shaft need to be brought about by an axial displacement of the operating knob.
In general, the ergonomics needs to be the same, from the user""s point of view, as those of a xe2x80x9cmechanicalxe2x80x9d antitheft system to which he may have become accustomed, and in which introducing the key into the lock then starting to turn it corresponds to an identification step.
Whether the antitheft system be of the xe2x80x9cmechanicalxe2x80x9d type or of the xe2x80x9celectronicxe2x80x9d type, it needs to have means of holding the latch bolt in the pulled in or retracted position which are perfectly reliable so as to eliminate any risk of accidental immobilization of the steering column shaft while the vehicle is in use, particularly while it is traveling along.
Various designs are thus known whereby the latch bolt is, held radially in the pulled in retracted position by a latch bolt retaining member which is mounted so that it can move between an effaced or retracted position and an active latch bolt retaining position toward which it is elastically urged and in which a retaining finger belonging to the retaining member is accommodated in a complementary notch in the latch bolt.
The general desire of motor vehicle manufacturers, to standardize components and equipment within a range of vehicles and for various versions of the same model culminates in particular in the standardization of the overall design of the steering column and of its antitheft mechanism and, more particularly, the design of the cam/latch bolt/interrupter electromechanical assembly which in addition complies with a set of legal standards which further complicate its design and homologation.
The invention thus aims to provide a novel design of latch bolt retaining means which can be used both for a mechanical antitheft system and for an electronic antitheft system, which is reliable, and the size of which is particularly small.
In order to remedy these drawbacks, the invention proposes an antitheft system of the aforementioned type, wherein the member for retaining the latch bolt is mounted to slide in the housing parallel to the axis of displacement and of rotation of the manual control member, and wherein the finger for retaining the latch bolt is formed at the front free end of the latch bolt retaining member.
The design according to the invention particularly lends itself to being adapted to suit an electronic antitheft system in which the manual control member is overall in the form of a manual control knob which is connected in terms of axial translation and in terms of rotation to a control rod, the displacements of which, with respect to the housing of the antitheft system, are similar to the displacements of the shank of a mechanical key with respect to the stator of the barrel-type lock that accommodates it.
According to other features of the invention:
the displacement of the latch bolt retaining member toward its effaced rear axial position against its return spring is controlled by the backward axial displacement of the manual control member into its pulled back locked position;
a portion of the latch bolt located inside the housing has a transverse rear face in which the latch bolt retaining notch is formed which is open axially toward the rear and on which the finger for retaining the latch bolt car be accommodated;
when the steering column is in the locked position, She front free end of the latch bolt retaining member extends facing the rear transverse face;
the antitheft system comprises elastically deformable means for axially indexing the manual control member in its pulled back locked position and for retaining it in this position against the return force exerted on the latch bolt retaining member by its return spring;
the manual control member comprises a radial flange, the rear annular face of which collaborates with a control tab of the latch bolt retaining member which extends radially inward facing this annular face;
the manual control member has a tab for axially retaining the manual control member with respect to the housing that forms a stator, which extends radially outward from the peripheral edge of the flange and which is accommodated in axial sliding in a complementary slot belonging to the housing to allow the axial displacements of the manual control member between its two axial positions, namely its pulled back locked position and its pushed forward unlocked position;
the antitheft system comprises:
a motorized member, particularly an electromagnetic member, for immobilizing in terms of rotation the control member with respect to the housing and the release of which is brought about when a coded antitheft signal is furnished by an identification unit to an electronic circuit for controlling the immobilization member;
and a switch for initiating an interrogation and identification step, which is carried by the housing and which is initiated by the manual control member;
the manual control member comprises a front rotor which is mounted to rotate with respect to the housing forming a stator between two extreme angular positions, one of which corresponds to the angular position of rest, which controls the displacements of the latch bolt and which is axially immobilized with respect to the housing that forms the stator, and a rear control rod which is mounted to slide axially with respect to the rotor, to which it is connected in terms of rotation, between a pulled back locked position and an extreme pushed forward unlocked position;
the radial flange for controlling the latch bolt retaining member belongs to the rear control rod;
the elastically deformable means for axially indexing the manual control member in its pulled back locked position and for holding it in this position collaborate with a portion of the rear control rod;
the electromagnetic member for immobilizing the control member in terms of rotation collaborates with the front rotor to immobilize it in terms of rotation;
the electromagnetic immobilizing member is an axially oriented electromagnet, the core plunger of which is urged elastically into the deployed position by a return spring in such a way as to be accommodated in at least one immobilizing notch formed in the rotor when the latter is in its angular position of rest, and this can be returned electromagnetically to the retracted position in such a way as to release the manual control member in terms of rotation;
the immobilizing notch is formed in an annular rear face of the rotor of the manual control member;
the electromagnetic immobilizing member and the initiating switch belong to a subassembly constituting a subassembly attached in the housing;
the attached subassembly comprises a printed circuit board which carries the switch and the electromagnetic immobilizing member;
the printed circuit board is in the shape of a flat annulus oriented transversely;
the printed circuit board is oriented axially;
the rear axial end of the control rod is connected in terms of axial translation and in terms of rotation to an operating knob.